Light emitting devices such as light emitting diodes or laser diodes using Group III-V or II-VI compound semiconductor materials implement light with a variety of colors such as red, green and ultraviolet light based on thin film growth technologies and development of device materials, implement white light by using phosphor materials or combining two or more colors and have advantages such as low power consumption, semi-permanent lifespan, high response speed, safety and eco-friendliness, as compared to conventional light sources such as fluorescent lamps and incandescent lamps.
Accordingly, an application range of such a light emitting device has been extended to transmission modules of optical communication systems, light emitting diodes as replacements for cold cathode fluorescent lamps (CCFLs) constituting backlights of display devices such as liquid crystal displays (LCDs), and white light emitting diode lighting devices as replacements for fluorescent lamps or incandescent lamps, vehicle headlights and traffic lights.
A light emitting device package has a configuration in which a first electrode and a second electrode are disposed in a package body, and a light emitting device is disposed on the bottom of the package body and is electrically connected to the first electrode and the second electrode.
FIG. 1 is a sectional view illustrating a conventional light emitting device package.
The light emitting device package 100 includes a package body 110a, 110b or 110c to form a cavity structure and a light emitting device 140 disposed on the bottom of the cavity. A heat dissipation portion 130 may be disposed in a lower part of the package body 110a, 110b or 110c and the heat dissipation portion 130 and the light emitting device 140 may be fixed through a conductive adhesion layer.
A molding portion 150 disposed in the cavity protects the light emitting device 140 while surrounding the same. The molding portion 150 may include a phosphor 160. Light of a first wavelength region emitted from the light emitting device 140 may excite the phosphor 160 and light of a second wavelength region may be emitted from the phosphor 160.
FIG. 2 shows the region A1 or A2 of FIG. 1 in detail.
A wire 145 may contact the light emitting device 140 in the region A1 and contact an electrode pad 70 in the region A2. The wire 145 thinly and lengthily droops down to form a stitch shape in the region represented by S1 in FIG. 2A and the region represented by S2 in FIG. 2B.
As shown in FIG. 2A, the wire 145 contacts the electrode pad 70 to form a stitch and as shown in FIG. 2B, the wire 145 contacts a via hole electrode 80 provided in the package body 110b to form a stitch.
Although FIGS. 2A and 2B illustrate embodiments of the region A2 of FIG. 1, the wire 145 may contact the electrode pad or the via hole-type electrode provided on the light emitting device 140 in the region A1 of FIG. 1.
However, the conventional light emitting device package has the following problems.
In the case of the wire bonded as shown in FIG. 2B, a portion of the surface of the via hole electrode 80 may be depressed and, thus, the stitch of the wire may not be completely bonded to the via hole electrode.